Goal: Reduce table field definition clutter caused by single-purpose calculation fields while still creating complex reports, using FileMaker Pro.

FileMaker Pro has significant capabilities for reporting, but it can sometimes be frustrating creating calculation fields for everything you might want to see only for a single report. Wouldn’t it be nice to create “temporary” fields programmatically via a script that last only while running the report?

There is a way to do this, using the Evaluate function: Create a single calculation field with, say, 100 repetitions, and have it Evaluate calculation text in matching repetitions of a repeating Global Text field. It can be tricky to do this successfully and decrease the likelihood of breaking your report if fields are renamed. I delivered a presentation for the New York FileMaker Developers’ Group on creating a detailed report (simplified for the demo) with many columns, percentages of many values out of the total for multiple sub-summaries, all with only a pair of fields. Download the Dynamic Repeating Calculation Reports demo file to see more. One final note: the most important thing to remember to accomplish this successfully is to wrap every non-repeating field used in your calculations with the Extend() function, so the repeating calculation gets a value beyond its own first repetition.